Hindsight is 20/20, especially when it comes to second guessing the harrowing decisions that have to be made during wartime. But sometimes we have to be critical, if we hope to avoid repeating the mistakes of the past. With that in mind, here are the most egregious blunders made by the Western Allies during the Second World War.

Above photo: Alfred Palmer/OWI/LOC

A few caveats before we get started. I'm not going to include the blunders made by the Western Powers leading up to the war, nor am I going to include the mistakes made by the Russians (who were technically part of the grand alliance). Those both deserve lists of their own.

Also, I don't mean to pick on the Allies, here. Axis forces were equally blunderous — if not more so — than their enemies, especially after Hitler took command of the German army in December 1941. But as already noted, it's still worthwhile to be critical of the victorious forces.

YouTube user EmperorTigerstar has painstakingly mapped the changing front lines of World War II in…
Read more Read more

Finally, I made an effort to choose mistakes which spanned the entire war and all the war theatres. I also felt it important to draw-out both "high level" mistakes and those with more immediate, but brutal, impacts. Given the complexity of war, I'm not going to pretend for a moment that my list is definitive or complete; You, the reader, are more than welcome to be critical in the comments and add your own.

Here's the list, ordered chronologically:

1. The Failure to Attack Germany After It Invaded Poland

One of the worst mistakes of the Second World War occurred right at its outset. When the Nazis invaded Poland on September 1, 1939, both Britain and France declared war on Germany — and then promptly did nothing. Not only was this a betrayal of a trusted ally (France and Poland worked together to steal an Enigma machine, for example), it allowed Germany to walk unscathed through Poland at a time when they were ill prepared to defend themselves on two fronts (a theme that would reprise itself some five years later, the war in Italy notwithstanding).

Among the many things that computer science pioneer Alan Turing is remembered for was his…
Read more Read more

Image: Richard A. Ruppert via US Holocaust Memorial Museum

Indeed, Germany's generals were so afraid of an immediate counter-attack by Allied forces that they placed 46 infantry divisions — of which only 11 were fully trained — along Germany's western border. By contrast, France had, at least on paper, the ability to mobilize well over a hundred divisions, not including four divisions of the British Expeditionary Force. Indeed, as Field Marshal Erich von Manstein noted in his memoirs, Poland's situation was so dire that it's only option was to "hold out until an offensive by the Western Powers compelled the Germans to withdraw the mass of their forces from the Polish theatre." An attack that, regrettably for them, never came.

The subsequent failure to attack Germany, despite the proclamation of war, gave Germany an entire year to prepare for its attack on France. It also sent a message, whether true or not, that the Western Powers weren't prepared to intervene with any kind of military resolve. And as a final aside, as France's ultra-defensive Maginot line indicated, the country was clearly not thinking about offense. As we'll see next, its military planners were anticipating a strategic repeat of World War I.

2. The Failure to Anticipate a German Blitz Through the Ardennes

Sure, Manstein's Sickle Cut Plan may be one of the greatest strategic maneuvers of the Second World War, if not of all military history — but it takes two to tango. The French completely failed to notice the German build-up along its eastern border, thinking that the Germans would simply repeat the pattern of 1914. And when the first wave of the attack came, it most certainly appeared that way. Allied forces rushed north, only to be outflanked by the Germans to the south, resulting the the so-called Miracle of Dunkirk.

Hitler in Paris, June 23, 1940. Credit: US National Archives and Records Administration (NARA)

But worst of all — and this is the big mistake here — the French had no strategic reserves left to deal with the Germans now flooding in unscathed; the door to Paris was wide open. The Blitzkrieg, which left the Allied forces completely dazed, caused France to fall in just six weeks.

3. America's Failure to Immediately Adopt the Convoy System

By the time the United States entered the war, the British had extensive experience dealing with German U-Boat tactics in the North Atlantic (including World War I). By sending chunks of convoys comprised of 30 to 70 ships, they stood a far better chance of avoiding detection, and then dealing with and dispatching U-Boats when they attacked. It was an anti-submarine tactic that worked; the math proved it. But owing to a confluence of factors, including Admiral King's unwillingness to press the issue, and the fact that the US failed (and underestimated the need) to produce the required number of escort ships, the United States did not adopt the convoy system until May 1942. By the time the change was made, the US suffered disastrous shipping losses — two million tons lost in January and February alone.

4. Underestimating the Japanese

Only old folks will remember this, but before World War Two the Japanese were widely regarded as sub-human barbarians incapable of original thought. Their military was regarded as a pathetic attempt to copy the obviously superior western militaries, and there was no doubt their forces would prove no match for western forces. This had many results, the first was that for the most part the Allies only had second string troops and leaders in Asia to defend against Japan. Secondly, the Allies made little effort to study the Japanese military and truly assess its capabilities. Lastly it resulted in Japan conquering more territory in the first six months of the war than any conquerer in history. That's right, the initial Japanese advance in World War Two was the greatest conquest in history. Pretty slick trick for sub-human barbarians.

Just to illustrate how racist and/or ignorant Americans were back then, it was a commonly held belief that Japanese troops couldn't see very well in the dark.

5. The Utterly Useless Raid on Dieppe

Historians are still scratching their heads over this one — as are Canadians. On August 19, 1942, 5,000 Canadian infantry, along with a thousand British troops (many of them commandos) attacked the French port of Dieppe on the English Channel Coast. It was supposedly an attempt to occupy Nazi-held land in Europe, but it ended in complete disaster. After nine hours of bitter fighting against a prepared and alert enemy, over 1,000 soldiers were dead and 2,000 taken prisoner. The resulting air battle cost the Allies 106 aircraft to Germany's 48.

Some historians speculate that it was an attempt by Churchill to show the United States how difficult an attack on European soil would be. Historian David O'Keefe claims it was actually a massive commando raid — the goal of which was to capture a Nazi Enigma machine. At the very least, it showed the Western Powers what it would take to secure a beachhead — something that wouldn't happen until D-Day some two years later.

6. FDR's Demand of "Unconditional" German Surrender

At the Allied Casablanca Conference in January 1943, US President Roosevelt gave a speech in which he demanded the "unconditional surrender" of Germany. It was an impromptu and utterly thoughtless remark that stunned a completely unsuspecting Winston Churchill. Prior to that stage, nothing had been formally decided about how to end the war — but now the die was cast.

FDR Library Photo Collection

Nazi Germany's diabolical propaganda minister, Joseph Goebbels, was jubilant, claiming he could never have dreamt up a more effective strategy to persuade the doomed Germans to fight to the last breath. Historians Agostino von Hassell and Sigrid Macrae write:

Goebbels's propaganda was shrieking that all Germany would be enslaved; there was no alternative but to fight to the bitter end. [Allen] Dulles quickly changed his mind [about the policy of unconditional surrender]. He came to agree with the opposition that Goebbels had been handed an extraordinary coup. Backing the nation into this cul de sac could only prolong the war. He also knew about the stab-in-the-back theory promulgated by conservatives after Versailles—namely that Germany had not really lost the war militarily, but that revolutionaries and democrats on the home front had stabbed the army in the back. Generals Hindenburg and Ludendorff had an interest in camouflaging the German defeat, and blamed it on insufficiently patriotic factions on the home front. Hitler had exploited this theory expertly.

Indeed, the demand of unconditional surrender does much to explain the fanatical resistance exerted by the Germans in the weeks and days leading up to the end of the war. And the infamous Morgenthau plan didn't help either — the plan to de-industrialize Germany after the war and turn it into an agrarian state.

7. The Failure to Seize the Early Initiative At Anzio

By early 1944, the German forces fighting in Italy were forced back along their Winter Line. Eager to restore mobility to the Italian Campaign, Allied commanders drummed-up Operation Shingle — an amphibious landing in the area of Anzio and Nettuno designed to outflank German forces and enable an attack on Rome. The invasion got off to a good start on January 22, 1944, catching the Germans by surprise — but the immediate objective of outflanking the Gustav Line completely failed. And that's when things got ugly, resulting in a World War One-like battlescape that Hitler himself called the "Anzio abscess."

During the four months of bitter fighting, the Anzio Campaign cost the Allies over 66,200 casualties (of which 37,000 were noncombat casualties). German figures were comparable.

Anzio failed to be the panacea the Allies sought. As General Lucas repeatedly stated before the landing, which he always considered a gamble, the paltry allotments of men and supplies were not commensurate with the high goals sought by British planners. He steadfastly maintained that under the circumstances the small Anzio force accomplished all that could have been realistically expected. Lucas' critics charge, however, that a more aggressive and imaginative commander, such as a Patton or Truscott, could have obtained the desired goals by an immediate, bold offensive from the beachhead. Lucas was overly cautious, spent valuable time digging in, and allowed the Germans to prepare countermeasures to ensure that an operation conceived as a daring Allied offensive behind enemy lines became a long, costly campaign of attrition.

8. The Premature and Overly Ambitious Operation Market Garden

This is the military engagement that Bernard Montgomery haters love to hate. Immortalized in the classic film, A Bridge Too Far, it was an airborne attack deep in Germany's rear areas that commenced in mid-September 1944. The plan was to send airborne troops along a narrow corridor extending approximately 80 miles (128 km) into Holland from Eindhoven northward to Arnhem.

Recreation of the massive parachute drop from A Bridge Too Far

The troops were supposed to secure bridges across a number of canals as well as across three major water barriers. But the troops were met by ferocious resistance each step of the way and quickly became overextended. By the end of the conflict, Allied troops lost somewhere between 15,300 to 17,000 troops, while the Germans may have suffered as little as 3,300 casualties (though estimates are incomplete, and could be as high as 13,000). When planning for Market Garden, the Allied leaders were clearly overconfident, riding high on their recent successes, while mistakenly thinking the Germans were done. It became very clear at this point that the war would not be over by Christmas.

Final Thoughts

This is, of course, an incomplete and highly subjective list. Many other "blunders" may belong on this list, including the failure at Kasserine Pass, the inability of the US and British to produce quality tanks (and in the case of the latter nation, effective anti-tank guns), Churchill's untimely decision to send troops to Greece in 1940, General Mark Clark's failure to cut off the German Army in Operation Diadem, the various mistakes made early-on in France after D-Day, the US habit of sending inexperienced troops directly to the front lines, and on and on.

More controversially (and conceptually), there's Eisenhower's failure to prevent the German evacuation from Sicily and his reluctance to beat the Soviets to Berlin. Some would even argue that the Allies made the mistake of not continuing to take the fight to the Soviets, thus preventing the rise of the Iron Curtain, and quite possibly the Cold War. But given how strong the Soviets were at that point, such a decision would have led to certain disaster — with Stalin pushing into France and claiming all of Europe for himself. But then again, the Americans were on the verge of developing the atom bomb. So many considerations....